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Title: Determinant quantum Monte Carlo study of d -wave pairing in the plaquette Hubbard hamiltonian

We used the determinant Quantum Monte Carlo (DQMC) to determine the pairing and magnetic response for a Hubbard model built up from four-site clusters - a two-dimensional square lattice consisting of elemental 2x2 plaquettes with hopping t and on-site repulsion U coupled by an interplaquette hopping t' ≤ t. Superconductivity in this geometry has previously been studied by a variety of analytic and numeric methods, with differing conclusions concerning whether the pairing correlations and transition temperature are raised near half-filling by the inhomogeneous hopping or not. For U/t = 4, DQMC indicates an optimal t'/t ≈ 0.4 at which the pairing vertex is most attractive. We also found that optimal t'/t increases with U/t. We then contrast our results for this plaquette model with a Hamiltonian which instead involves a regular pattern of site energies whose large site energy limit is the three band CuO 2 model; we show that there the inhomogeneity rapidly, and monotonically, suppresses pairing.
 [1] ;  [2] ;  [1] ;  [3] ;  [4] ;  [4]
  1. Harbin Inst. of Technology (China). Dept. of Physics
  2. Pennsylvania State Univ., University Park, PA (United States). Physics Dept.; Univ. of California, Davis, CA (United States). Physics Dept.
  3. Federal Univ. of Rio de Janeiro (Brazil). Inst. of Physics
  4. Univ. of California, Davis, CA (United States). Physics Dept.
Publication Date:
OSTI Identifier:
Grant/Contract Number:
NA0001842; NA0001842-0
Accepted Manuscript
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 90; Journal Issue: 7; Journal ID: ISSN 1098-0121
American Physical Society (APS)
Research Org:
Univ. of California, Davis, CA (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States